One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,5,7,8)(12,20)(16,23)(18,24)(21,22)(25,26)(27,32)(28,34)(29,38)(30,33)(31,35)(36,39)(37,40)(1,2)(3,5)(4,6)(7,8)(9,10)(11,15)(12,16)(13,17)(14,19)(18,22)(20,23)(21,24)(25,27,31,38)(26,32,35,29)(28,36,30,37)(33,40,34,39)(9,11)(10,14)(12,18)(13,19)(15,17)(16,21)(20,24)(22,23)(25,28,31,30)(26,33,35,34)(27,36,38,37)(29,39,32,40)(1,3,4,7)(2,5,6,8)(9,11)(10,15)(12,18)(13,19)(14,17)(16,22)(20,24)(21,23)(25,29)(26,27)(28,39)(30,40)(31,32)(33,36)(34,37)(35,38)(9,10)(11,14)(12,16)(13,17)(15,19)(18,21)(20,23)(22,24)(25,26)(27,32)(28,33)(29,38)(30,34)(31,35)(36,40)(37,39) involution — undirected(9,12,13,20)(10,16,17,23)(11,18,19,24)(14,21,15,22)(25,30,31,28)(26,34,35,33)(27,37,38,36)(29,40,32,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.